So what happens when that wonderful adventure you put together, with all its interesting surprises and nasty traps, gets circumnavigated by the party because they have some nifty spells and additional tricks up their sleeve you didn’t think about?

Aside from taking it on the chin and continuing in the spirit of fun, there’s not much you can do for that session. But it can give you some ideas to prevent said players from getting out of similar traps next time:

1) Use a trap that breaks concentration. Something that projects loud noise, for instance. Have them save each round in order to keep their concentration up (you have to be fair, after all).

2) Make traps only respond to human/humanoids, or have a weight limit. Using the poor mascot or familiar to activate a trap is just nasty, but some parties do that sort of thing. Think about your trap set up for next time: perhaps the mechanism is too complicated for an animal or it’s too light to activate it.

3) Surround your mechanically-based traps with an Anti-Magic Shell. No magic works inside its 10 foot radius sphere. Take that, player characters…

4) Trap the walls or the air. Now this is really evil. If the characters climb up the walls to avoid the trapped floor, the wall trap triggers. If they fly over the floor the air trap triggers. Bwah ha ha!

5) Make their spells go haywire. If the characters cast a Fly spell in the trapped area, make the spell go crazy and fly them straight into the wall, damaging them and possibly breaking their concentration. If they persist, have the spell go crazier still. You can ad lib the various effects if needed. You’re the DM, after all.

In the end, the whole point of traps is to challenge the players and let them have a good time figuring it out. Yeah, you can make them hard, but they shouldn’t be impossible. You want some of them to survive to play another day, don’t you?